In order to implement photon counting type CT (Computed Tomography), a detector including a signal processing circuit (DAS: Data Acquisition System) capable of performing energy discrimination and optimal X-ray detection elements is required. For this reason, a photon counting type CT is higher in manufacturing cost and management cost than an integral type CT. In addition, the integral type CT acquires a signal corresponding to the energy integration of X-ray photons for each view, whereas the photon counting type CT acquires a signal corresponding to the count value of X-ray photons for each energy band concerning each view. Therefore, the amount of data of signals acquired by the photon counting type CT is larger than that acquired by the integral type CT by the energy resolution. A solution to the above technical problem is indispensable to the commercial success of the photon counting type CT.